The invention relates to a stationary thread-guiding element to a series shed weaving machine.
A weft thread distributor apparatus of a series shed weaving machine with air jet insertion is known from the patent specification EP 0 433 216 B1. A series shed weaving machine of this kind comprises a rotor which is rotatably journalled about an axis of rotation and at the surface of which a plurality of weft insertion passages are regularly arranged with spacing in the direction extent of the axis of rotation and in the peripheral direction in order to be able to insert a plurality of weft threads, in particular four weft threads, into the weaving rotor at the same time. A weft thread distributing apparatus is arranged at an end face of the weaving rotor and has the task of supplying the weft threads from the stationary supply apparatus to the rotating weaving rotor in such a manner that each weft thread enters into that weft insertion passage through which the weft thread is to be inserted. For this the weft thread distributing apparatus comprises a stationary thread guiding element and a thread guiding element which rotates with the weaving rotor. The known series shed weaving machine uses two circular thread guiding elements, one stationary and one co-rotating thread guiding element, which are formed of metal and which have a plurality of grooves at the end faces through which the weft thread is led. The two end faces either lie one against the other during operation, which leads to a mutual wear; or they are arranged in such a manner that an air gap forms between the two end faces, with it being possible for very thin yarns to enter into this air gap, which leads to a faulty insertion. It is also disadvantageous that contamination accumulates between the end faces during the operation of the series shed weaving machine, which increases the mutual spacing of the two end faces and increases the probability of additional faulty insertions.
The object of the invention is to propose an economically more advantageous thread guiding element.
The object is satisfied in particular by a stationary thread guiding element for a series shed weaving machine which has a plurality of concentrically extending grooves at an end face, with the thread guiding element being designed as a circular segment or as a circular sector.
An advantage of the stationary thread guiding element in accordance with the invention is that the thread guiding element is shaped as a circular segment or as a circular sector and extends for example over an angular range between 30xc2x0 and 180xc2x0, and preferably over 120xc2x0. Through this, on the one hand, the mutual wear of the stationary and the co-rotating thread guiding element is reduced, since their two end faces no longer lie completely against one another, but rather only along the end face which is formed by the stationary thread guiding element. A further advantage is that the accumulation of contamination between the two mutually contacting end faces is reduced, since the end face of the rotor is no longer completely covered over, so that the contamination either falls out by itself or for example is removed with the assistance of additional fluid nozzles which are directed towards the end face.
In an advantageous embodiment the stationary thread guiding element extends over an angular range of 120xc2x0. The stationary thread guiding element is thereby very economical to manufacture in that in a first manufacturing step a circular body containing the thread guiding elements is processed and is separated into three equally large parts in a subsequent method step so that three stationary thread guiding elements arise, with each thread guiding element extending substantially over 120xc2x0. In a further, advantageous embodiment the stationary thread guiding element consists of a material containing solid lubricants or of a material consisting of a solid lubricant which has a powder-like abrasion during wear, in particular of graphite or PEEK. These materials also have the advantage that the stationary thread guiding element can lie in contact on the end face of the thread guiding element which co-rotates with the weaving rotor, and that no air gap or only a small air gap arises between the end faces of the stationary and the co-rotating thread guiding element. Through this it is also possible to supply very thin yarns and filaments reliably to the weaving rotor without these threads, or fibrils of these threads, being able to enter into a gap between the stationary and the rotating thread guiding elements.
The stationary thread guiding element is preferably designed in such a manner that it is considered to be a part which is subject to wear and that it can be replaced in a very simple and rapid manner. For this, corresponding holding apparatuses are arranged at the stationary part of the series shed weaving machine or at the stationary part of the weft thread distributing apparatus respectively.